Bio-Module6-Chapter12, Genetic Engineering Applications, Bio-Module5-Chapter10, Bio-Module5-Chapter9, Bio-Module6-Chapter15,16,17, Bio-Module6-Chapter14, Bio-Module6-Chapter13

Adaptation:

inherited trait that permits an organism to survive and reproduce.

Allele frequency:

number of copies of one allele, divided by the number of alleles in a population.

Artificial selection:

selective breeding strategy in which a human allows only organisms with desired traits to reproduce.

Bottleneck effect:

genetic drift that occurs as a result of a sudden reduction in the size of population.

Directional selection:

form of natural selection in which one extreme phenotype is fittest, and the environment selects against the others.

Disruptive selection:

form of natural selection in which the two extreme phenotypes are fittest.

Evolution:

descent with modification: change in allele frequencies in a population over time.

Founder effect:

genetic drift that occurs when a small, nonrepresentative group of individuals leaves their ancestral population and begins a new settlement.

Gene pool:

all of the genes and their alleles in a population.

Genetic drift:

change in allele frequencies that occurs purely by chance.

Hardy-Weinberg equilibrium:

situation in which allele frequencies and genotype frequencies do not change from one generation to the next.

Macroevolution:

large-scale evolutionary change.

Microevolution:

relatively short-term changes in allele frequencies within a population or species.

Modern evolutionary synthesis:

the idea that genetic mutations create the variation upon which natural selection acts.

Mutation:

a change in a DNA sequence.

Natural selection:

differential reproduction of organisms based on inherited traits.

Population:

interbreeding members of the same species occupying the same region.

Sexual dimorphism

difference in appearance between makes and females.

Sexual selection:

type of natural selection resulting from variation in the ability to obtain mates

Stabilizing selection:

form of natural selection in which extreme phenotypes are less fit that the optimal intermediate phenotype.

Why can't evolution act on individuals?

Evolution cannot act directly on individuals because evolutionary change emerges through differential reproductive success across populations over multiple generations. Individual organisms don't evolve themselves.

What is Lamarckian Evolution? Why does the "inheritance of acquired characteristics" NOT explain how evolution works?

Lamarckian Evolution proposed that acquired characteristics could be inherited, which is incorrect. Evolution works through the process of natural selection acting on random genetic variations that are inherited.

In what ways did Thomas Malthus's Essay on the Principle of Population influence Darwin? How did the work of other scientists influence Darwin's thinking?

Malthus' essay influenced Darwin by describing how population growth outpaces food supply, suggesting a struggle for existence. The work of geologists like Lyell on gradual changes over long time periods also influenced Darwin.

What is artificial selection? and why does it provide evidence for unequal reproductive success?

Artificial selection is the selective breeding of organisms with desired traits by humans, providing evidence that selecting which individuals reproduce can accumulate specific traits over generations.

Define natural selection. Describe the observations and inferences that support the theory of natural selection

Natural selection is the differential survival and reproduction of individuals with favorable heritable traits that increase fitness in a specific environment.

What are adaptations?

Adaptations are inherited characteristics that enhance an organism's ability to survive and reproduce in its environment.

Review Table 12.1

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What is the role of genetic variation in natural selection?

Genetic variation is the raw material upon which natural selection acts, allowing some variants to increase in frequency if they confer higher fitness.

What is fitness, in the context of evolution?

In evolution, fitness refers to the ability of an individual to survive and reproduce relative to other individuals in the population.

What assumptions must be met for a population to be in Hardy Weinberg equilibrium?

The Hardy-Weinberg assumptions are: random mating, no gene flow, no mutation, no selection, infinitely large population.

List and describe five mechanisms of evolution

Five mechanisms:
1) mutation
2) genetic drift
3) gene flow
4) natural selection
5) nonrandom mating

What is sexual selection?

Sexual selection acts through mate choice and competition for mates, leading to traits that increase mating success.

Explain how mutation, genetic drift and migration (aka gene flow) may cause evolution

Mutation generates new variation, drift randomly changes allele frequencies, and gene flow introduces new variation from other populations.

Review the "Pull it all together" Diagram, Figure 12.24

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Transgenic organism

Organism with foreign DNA inserted for specific traits

Electrophoresis gel

Separates DNA strands based on size

DNA profiling

Identifying individuals based on unique DNA patterns

PCR

Polymerase chain reaction amplifies DNA segments

Reproductive cloning

Creating a genetic copy of an organism

Therapeutic cloning

Producing stem cells for medical purposes

Stem cells

Undifferentiated cells with regenerative potential

Embryonic stem cells

Derived from embryos, pluripotent potential

Adult stem cells

Found in tissues, limited differentiation potential

Describe the differences between phenotype and genotype, dominant and recessive, homozygous and heterozygous, codominance and incomplete dominance.

Phenotype is the observable traits, genotype is the genetic makeup. Dominant traits are expressed over recessive. Homozygous means two identical alleles, heterozygous means two different alleles. Codominance means both alleles are fully expressed, incomplete dominance means a blend of traits is expressed.

What are monohybrid and dihybrid crosses? (be able to work through examples)

A monohybrid cross follows one gene, a dihybrid cross tracks two genes simultaneously.

What is the law of segregation?

The law of segregation states that paired alleles separate during gamete formation so offspring get one from each parent.

What is the law of independent assortment?

The law of independent assortment states that segregation of different genes is independent during gamete formation.

Cystic fibrosis (CF) is caused by a recessive allele. A child has CF, even though neither of his parents has CF. This couple also has a child who does not have CF. What is the probability he or she is homozygous?

If the child has the recessive CF trait but neither parent shows CF, both parents must be heterozygous carriers. The probability the other child is homozygous recessive (affected) is 25%.

Which type of inheritance is most likely to display a bell curve of phenotypes?

Incomplete dominance and codominance tend to show a bell curve of phenotypes.

ABO blood types are an example of which type of inheritance?

ABO blood groups exhibit codominance/multiple alleles expressed.

What are homologous chromosomes? In what way are each matched? In what way to each differ?

Homologous chromosomes are matched pairs of chromosomes, one inherited from each parent. They have the same genes in the same order and locations, but may have different alleles. They pair up during meiosis.

What are the advantages of sexual and asexual reproduction? How do they compare? Make a Venn Diagram comparing them.

Sexual reproduction allows genetic variation through combining DNA from two parents, while asexual reproduction produces genetically identical offspring. A Venn diagram would show advantages like genetic diversity vs reproductive efficiency in the intersecting regions.

Fruit flies (Drosophila) produce gametes that contain four chromosomes each. Draw a karyotype for a Drosophila brain cell. Is the cell diploid or haploid? What does that mean?

A diploid Drosophila brain cell karyotype would show 8 chromosomes (4 homologous pairs). Diploid means the full chromosome complement from both parents. Gametes are haploid, with one copy of each chromosome.

What would happen if germ cells divided by mitosis instead of meiosis? Is there any circumstance where this would be a good idea?

If germ cells divided by mitosis instead of meiosis, they would remain diploid, preventing sexual reproduction. This does occur in some parthenogenetic species that reproduce asexually.

How does meiosis reduce the number of chromosomes by half? Why is this important

Meiosis reduces chromosome number by half through two nuclear divisions following one round of DNA replication. This is crucial to maintain the diploid number after fertilization combines gametes.

Compare and contrast meiosis versus mitosis. Where does meiosis occur?

Meiosis has two divisions producing 4 haploid gametes, while mitosis has one division producing two diploid daughter cells. Meiosis occurs in sexual reproduction compartment to produce gametes.

Who determines the sex of a child - mom, dad or both mom and dad? Explain

Typically the male determines the sex in mammals through X/Y chromosomes.

anaerobic respiration

cellular respiration using an electron acceptor other than O2.

aerobic respiration:

complete oxidation of glucose to CO2 in the presence of O2, producing ATP.

archaea:

one of two domains of prokaryotes.

autotroph:

organism that produces organic molecules by acquiring carbon from inorganic sources: a primary produces.

bacteria:

one of two domains of prokaryotes.

chemotroph:

organism that derives energy by oxidizing inorganic or organic chemicals.

endosymbiont theory:

the idea that mitochondria and chloroplasts originated as free-living bacteria engulfed by other cells.

heterotroph:

organism that obtains carbon and energy by eating another organism: a consumer.

phototroph:

organism that derives energy from sunlight.

prokaryote:

A cell that lacks a nucleus and other membrane-bounded organelles: bacteria and archaea.

protist:

eukaryotic organism that is not a plant, fungus, or animal.

fungi:

kingdom containing mostly multicellular eukaryotes that are heterotrophs by external digestion.

mycelium:

assemblage of hyphae that forms an individual fungus.

hypha (pl. hyphae):

a fungal filament; the basic structural unit of a multicellular fungus.

angiosperms:

a seed plant that produces flowers and fruits: including monocots and eudicots.

bryophytes:

plant that lacks vascular tissue: includes liverworts, hornworts, and mosses.

gymnosperms:

a plant with seeds that are not enclosed in a fruit: includes conifers, ginkgo, gnetophytes, and cycads.

seedless vascular plants:

plant with vascular tissue but not seeds; includes true ferns, club mosses, whisk ferns, and horsetails.

animalia:

kingdom containing multicellular eukaryotes that are heterotrophs by ingestion.

arthropod:

segmented animal with an exoskeleton and joined appendages: phylum Arthropoda.

chordate:

animal that at some time during its development has a notochord. a hollow nerve cord, pharyngeal slits or pouches, and a postanal tail: phylum Chordate.

mammal:

type of tetrapod vertebrate with hair and mammary glands: embryo is enclosed in an amnion.

primate:

mammal with opposable thumbs, eyes in front of the skull. a relatively large brain. and flat nails instead of claws: includes prosimians, monkeys, and apes.

Vertebrate:

animal with a backbone.

List a logical sequence of evolutionary events that starts with a prokaryote and ends with a multicellular eukaryote.

a) Prokaryotes (bacteria and archaea) evolved around 3.5 billion years ago.
b) Endosymbiotic event: A prokaryote engulfed another prokaryote, leading to the formation of the first eukaryotic cell with a nucleus and membrane-bound organelles like mitochondria and chloroplasts.
c) Unicellular eukaryotes evolved, including protists.
d) Multicellular eukaryotes evolved from unicellular eukaryotes, first appearing as colonial organisms.
e) Differentiation of cells and tissues led to the development of complex multicellular eukaryotes, such as animals, plants, and fungi.

In what ways are bacteria and archaea important to eukaryotic life in general and to human life in particular?

a) Decomposers: They play crucial roles in recycling nutrients and breaking down organic matter, making nutrients available for other organisms.
b) Producers: Some bacteria and archaea are photosynthetic and contribute to primary production, forming the base of many food chains.
c) Symbiotic relationships: Many eukaryotes, including humans, have symbiotic relationships with bacteria and archaea, which are essential for various processes like digestion, nutrient acquisition, and immune function.
d) Biotechnology: Bacteria and archaea are widely used in biotechnology for the production of foods, drugs, and other industrial products.
e) Ecological roles: They play vital roles in biogeochemical cycles, such as nitrogen fixation, sulfur cycling, and methane production.

What features define the protists? Give examples of different types of protists.

a) Unicellular or simple multicellular organization.
b) Diverse modes of nutrition (autotrophic, heterotrophic, or mixotrophic).
c) Diverse modes of reproduction (asexual, sexual, or both).
d) Diverse habitats (aquatic, terrestrial, or parasitic).

Describe the reproductive adaptations of different groups of land plants.

+Plant reproductive adaptations:
- Bryophytes (spores, alternation of generations),
- seedless vascular plants (sporophyte dominant, spores),
- gymnosperms (naked seeds, wind/insect pollination),
- angiosperms (seeds in fruits, diverse pollination).

How are seedless vascular plants similar to and different from bryophytes? What are differences between gymnosperms and angiosperms?

- Similarities of seedless vascular plants and bryophytes: Alternation of generations, spore reproduction.
- Differences: Vascular tissue in seedless plants, sporophyte vs. gametophyte dominance. Gymnosperm vs. angiosperm: Naked vs. enclosed seeds, pollination modes, flowers.

What features do all animals share in common?

Multicellular, heterotrophic, no cell walls, motility, sexual reproduction, specialized tissues.

Describe the characteristics of chordates. Then, what makes mammals unique from other groups of vertebrates (like fish, amphibians and reptiles).

- Chordate features: Notochord, dorsal nerve cord, pharyngeal slits/pouches, post-anal tail.
- Mammals: Endothermic, hair, milk, specialized jaws, diaphragm breathing, four-chambered heart.

Allopatric speciation:

formation of new species after a physical barrier separates a population into groups that cannot interbreed.

Background extinction rate:

steady, gradual loss of species through natural competition or loss of genetic diversity.

Biological species:

a population. or group of populations whose members can interbreed and produce fertile offspring.

Extinction:

death of all individuals of a species.

Gene pool:

all of the genes and their alleles in a population.

Gradualism:

theory that proposes that evolutionary changes occurs gradually, in a series of small steps.

Hybrid (genetics):

producing a mix of offspring for one or more traits; heterozygous.

Macroevolution:

large-scale evolutionary change.

Mass extinction:

the disappearance of many species over relatively short expanses of time.

Postzygotic reproductive barrier:

separation of species due to selection against hybrid offspring.

Punctuated equilibrium:

theory that life's history has been characterized by bursts of rapid evolution interrupting long periods of little change.

Reproductive barrier:

mechanism that prevents groups of organisms from sharing a gene pool.